Catalytic combustion heating system suitable for high-concentration hydrogen

Abstract

The utility model discloses a catalytic combustion heating system suitable for high-concentration hydrogen, which is characterized in that a gas mixer is arranged on an air pipeline, a mass flow control meter, an electromagnetic valve and a flame arrester are arranged on a hydrogen pipeline, and hydrogen is injected into the gas mixer to be mixed with air; a flame arrester, a gas rectifier, an integral honeycomb carrier catalyst, a self-reaction area and a pipeline back pressure valve are sequentially arranged on the mixed gas pipeline and are connected through flanges and heat insulation gaskets, and a hydrogen concentration sensor is arranged at an outlet of a gas mixer; temperature sensors are arranged at multiple positions of the mixed gas pipeline so as to measure the gas temperature at different positions. The hydrogen concentration ranges from 4% to 20%, hydrogen-oxygen exothermic reaction is started in a catalytic ignition mode so as to induce hydrogen-oxygen self-reaction, the catalytic ignition low-temperature starting speed can be controlled, high-temperature inactivation of a catalyst is avoided, the overall structure is compact, airflow is stable, tempering risks are avoided, and heat energy and kinetic energy can be provided for scenes such as high-temperature steelmaking and turbine power generation.

Description

Technical Field

[0001] The utility model relates to a hydrogen combustion heating device, in particular to a catalytic combustion heating system based on high-concentration hydrogen, and belongs to the field of efficient and clean utilization of hydrogen. Background Art

[0002] As a clean energy source, hydrogen has a significant thermal effect when it is burned with air (oxygen). High-temperature gas outputs of different temperatures can be obtained by changing the concentration of hydrogen. The high-temperature gas after the reaction is directly used in power generation equipment to be converted into electrical energy, or used in high-temperature heating systems. In the field of high-temperature heating, such as above 1000°C, the concentration of hydrogen in the mixed gas is within the extreme explosion range (4%-75%). Traditional ignition methods such as spark ignition or flame ignition will cause the hydrogen-oxygen complex reaction to be too violent and difficult to control, and even have the risk of explosion.

[0003] In the presence of precious metal catalysts such as Pd and Pt, the hydrogen-oxygen reaction can be initiated at room temperature (25°C), but existing hydrogen catalytic combustion devices cannot effectively control the ignition rate and temperature, which can easily cause flashback and damage the burner, and cannot guarantee safety under high hydrogen concentration conditions. Utility Model Content

[0004] In order to solve the problems of too fast reaction rate, easy backfire and poor safety in the high-concentration hydrogen combustion process, the utility model proposes a catalytic combustion heating system suitable for high-concentration hydrogen, which is suitable for the high-temperature pressurized heating field with a hydrogen concentration of 4%-20%. The hydrogen and oxygen exothermic reaction is started by catalytic ignition to induce the self-reaction of hydrogen and oxygen. The catalytic ignition low-temperature start-up rate is controllable to avoid high-temperature deactivation of the catalyst. At the same time, the overall structure is compact, the airflow is smooth, and there is no risk of backfire. It can provide thermal energy and kinetic energy for high-temperature steelmaking, turbine power generation and other scenarios.

[0005] The technical solution of the utility model is as follows:

[0006] A catalytic combustion heating system suitable for high-concentration hydrogen comprises an air pipeline, a hydrogen pipeline and a mixed gas pipeline, and is characterized in that a gas mixer is arranged on the air pipeline, and a mass flow controller, a solenoid valve and a hydrogen pipeline flame arrester are arranged on the hydrogen pipeline; the hydrogen pipeline is connected to the gas mixer to mix hydrogen with air; the outlet of the gas mixer is connected to the mixed gas pipeline, and a main pipeline flame arrester, a gas rectifier, an integral honeycomb carrier catalyst, a self-reaction zone and a pipeline back pressure valve are arranged in sequence on the mixed gas pipeline; a hydrogen concentration sensor is arranged at the outlet of the gas mixer, and temperature sensors are arranged at multiple locations on the mixed gas pipeline to measure the gas temperature at different positions.

[0007] Furthermore, the integral honeycomb carrier catalyst and the self-reaction zone are arranged in the same section of the pipeline, wherein the integral honeycomb carrier catalyst is located at the front of the pipeline, followed by the self-reaction zone. Flange connections are used between the gas mixer and the main pipeline flame arrester, between the main pipeline flame arrester and the gas rectifier, and between the gas rectifier and the pipeline where the integral honeycomb carrier catalyst is located. Preferably, a heat insulating gasket is arranged between the flanges to prevent the heat of the hydrogen-oxygen reaction from being transferred to the front gas rectifier, the main pipeline flame arrester and the gas mixer. Furthermore, the pipeline where the self-reaction zone is located is also connected to the pipeline back pressure valve through a flange and a heat insulating gasket, and the rear end of the pipeline back pressure valve outputs high-temperature exhaust gas.

[0008] Furthermore, temperature sensors are respectively arranged at the inlet and outlet of the gas rectifier to measure the outer wall temperature of the inlet and outlet of the gas rectifier and monitor the heat transfer; temperature sensors are respectively arranged at the inlet and outlet of the integral honeycomb carrier catalyst and at the rear end of the self-reaction zone to monitor the inlet temperature of the integral honeycomb carrier catalyst, the temperature after catalytic ignition and the final outlet temperature of the system in turn, and the latter two temperatures are compared to determine whether the self-reaction is started.

[0009] Preferably, the hydrogen pipeline is vertically connected to the gas mixer.

[0010] The gas mixer can be a static mixer, a Venturi mixer, etc., and the degree of uniform mixing of hydrogen and air reaches more than 97%, thereby avoiding excessive local hydrogen concentration.

[0011] The integral honeycomb carrier catalyst is preferably an integral honeycomb ceramic-based carrier catalyst loaded with active metal Pt and γ-Al2O3, and its composition is active metal Pt / γ-Al2O3 / cordierite honeycomb ceramic, wherein the loading amount of Pt is 5‰-1%, the loading amount of γ-Al2O3 is 5%-15%, and the cordierite honeycomb carrier has a square pore structure, and the honeycomb pore diameter is 1.2mm~6.4mm.

[0012] The pore structure of the gas rectifier can be square, regular hexagonal, etc., which can reduce the turbulence and eddy current of the gas and make the gas flow rate more uniform.

[0013] Compared with the prior art, the utility model has the following advantages:

[0014] 1. The process of mixing high-concentration hydrogen with air is carried out at low temperature, without the risk of explosion;

[0015] 2. Catalytic ignition can be started at low temperature, ignite evenly, and have controllable efficiency, thereby inducing spontaneous hydrogen and oxygen reactions and avoiding high-temperature deactivation of the catalyst;

[0016] 3. The whole system has a simple structure, the gas flow rate is evenly distributed, the turbulence and eddy current in the gas flow process are reduced, the high-temperature gas backflow is avoided, and there is no risk of flashback;

[0017] 4. The rate and temperature of catalytic ignition can be effectively controlled by adjusting the active sites of the catalyst, the contact time between the reaction gas and the catalyst, the gas flow rate, etc. according to different outlet temperatures, hydrogen concentrations, and feed gas flow rates. After catalytic ignition, the heat released by part of the hydrogen-oxygen reaction causes the system temperature to reach above 550°C, and the hydrogen-oxygen reaction can proceed spontaneously until the hydrogen reaction is complete. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The utility model is a schematic diagram of the structure of a catalytic combustion heating system suitable for high-concentration hydrogen, wherein: 1. air pipeline; 2. thermal insulation gasket; 3. gas mixer; 4. main pipeline flame arrester; 5. gas rectifier; 6. integral honeycomb carrier catalyst; 7. self-reaction zone; 8. pipeline back pressure valve; 9. hydrogen pipeline; 10. mass flow controller; 11. solenoid valve; 12. hydrogen pipeline flame arrester; 13. hydrogen concentration sensor; 14-18, first to fifth temperature sensors. DETAILED DESCRIPTION

[0019] The technical solution of the utility model is described in detail below by embodiments in conjunction with the accompanying drawings. Unless otherwise defined, the technical terms used in the following embodiments have the same meanings as those generally understood by those skilled in the art.

[0020] Example 1

[0021] A catalytic combustion heating system suitable for high concentration hydrogen, such as Figure 1As shown, the air pipeline 1 is horizontally connected to the gas mixer 3, the hydrogen pipeline 9 is sequentially provided with a mass flow controller 10, a solenoid valve 11 and a hydrogen pipeline flame arrester 12, and the hydrogen is vertically injected into the gas mixer 3 to mix with the air, and the flow rate of the air in the gas mixer 3 is 0.5-25m / s, while the pressure and flow rate of the hydrogen are always kept higher than the pressure and flow rate of the air and the high-temperature tail gas outlet pressure to prevent air from entering the hydrogen pipeline. During operation, air is first introduced and then hydrogen is added, and the hydrogen concentration increases. The connection between the components in the pipeline is a flange, equipped with a thermal insulation gasket 2. The mixed gas passes through the main pipeline flame arrester 4 and the gas rectifier 5 in turn, and the first temperature sensor 14 and the second temperature sensor 15 are respectively provided at the inlet and outlet of the gas rectifier 5 to measure the outer wall temperature and monitor the heat transfer. Then, the mixed gas enters the integral honeycomb carrier catalyst 6 for catalytic ignition reaction. The loading amount of active metal of the integral honeycomb carrier catalyst 6 is 5‰ to 25‰, the loading amount of porous carrier γ-Al2O3 is 5 to 15%, the pore size of the honeycomb carrier is 1.2 to 6.4 mm, and the flow rate of the mixed gas through the integral honeycomb carrier catalyst 6 is 5m / s to 50m / s, and the air velocity is 100000h -1 ~300000h -1 . According to different air flow rates and hydrogen concentrations, the catalytic ignition rate is controlled by changing the pore size and length of the integral honeycomb carrier catalyst 6 and the active metal loading amount, and the catalytic ignition outlet temperature is controlled within 550-850°C to avoid the complete reaction of hydrogen and the catalyst sintering and deactivation at high temperature. The higher the hydrogen concentration in the air, the faster the flow rate and air velocity of the gas through the integral honeycomb carrier catalyst 6. After the integral honeycomb carrier catalyst 6 is catalytically ignited, part of the hydrogen reacts with the air to release heat, and the temperature at the outlet of the integral honeycomb carrier catalyst 6 rises to 550-850°C, and then enters the hydrogen-oxygen self-reaction zone 7. The third temperature sensor 16 is used to detect the inlet temperature of the integral honeycomb carrier catalyst 6, the fourth temperature sensor 17 is used to detect the outlet temperature of the integral honeycomb carrier catalyst 6, and the fifth temperature sensor 18 is used to detect the final outlet temperature. By comparing the fourth temperature sensor 17 and the fifth temperature sensor 18, it is determined whether the hydrogen-oxygen self-reaction is started. The pipeline back pressure valve 8 is used to adjust the system pressure, and can output high-temperature gas of different pressures. The pressure adjustment range is 0-6bar. All temperature sensors and concentration sensors can be interlocked with the mass flow controller 10 and the solenoid valve 11 on the hydrogen pipeline to improve system safety.

Claims

1. A catalytic combustion heating system suitable for high-concentration hydrogen, comprising an air pipeline, a hydrogen pipeline and a mixed gas pipeline, characterized in that: A gas mixer is arranged on the air pipeline, and a mass flow controller, a solenoid valve and a hydrogen pipeline flame arrester are arranged on the hydrogen pipeline; the hydrogen pipeline is connected to the gas mixer to mix hydrogen with air; the outlet of the gas mixer is connected to the mixed gas pipeline, and a main pipeline flame arrester, a gas rectifier, an integral honeycomb carrier catalyst, a self-reaction zone and a pipeline back pressure valve are arranged in sequence on the mixed gas pipeline; a hydrogen concentration sensor is arranged at the outlet of the gas mixer, and temperature sensors are arranged at multiple locations on the mixed gas pipeline to measure the gas temperature at different positions.

2. The catalytic combustion heating system according to claim 1, characterized in that: The integral honeycomb carrier catalyst and the self-reaction zone are arranged in the same section of the pipeline, wherein the integral honeycomb carrier catalyst is located at the front of the pipeline, and the self-reaction zone is located behind it.

3. The catalytic combustion heating system according to claim 2, characterized in that: Flange connections are adopted between the gas mixer and the main pipeline flame arrester, between the main pipeline flame arrester and the gas rectifier, and between the gas rectifier and the pipeline where the integral honeycomb carrier catalyst is located, and heat insulating gaskets are arranged between the flanges.

4. The catalytic combustion heating system according to claim 2, characterized in that: The pipeline where the self-reaction zone is located is connected to the pipeline back pressure valve by a flange, and a heat insulation gasket is arranged between the flanges.

5. The catalytic combustion heating system according to claim 1, characterized in that: Temperature sensors are respectively arranged at the inlet and outlet of the gas rectifier, the inlet and outlet of the integral honeycomb carrier catalyst, and the rear end of the self-reaction zone.

6. The catalytic combustion heating system according to claim 1, characterized in that: The hydrogen pipeline is vertically connected to the gas mixer.

7. The catalytic combustion heating system according to claim 1, characterized in that: The gas mixer is a static mixer or a venturi mixer.

8. The catalytic combustion heating system according to claim 1, characterized in that: The monolithic honeycomb carrier catalyst is a monolithic honeycomb ceramic-based carrier catalyst that carries active metal Pt and γ-Al2O3.

9. The catalytic combustion heating system according to claim 8, characterized in that: The honeycomb pore size of the monolithic honeycomb ceramic-based carrier catalyst is 1.2-6.4 mm.

10. The catalytic combustion heating system according to claim 1, characterized in that: The pore structure of the gas rectifier is a square or a regular hexagon.

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